Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-Cho, Fuchu, Tokyo, 183-8509, Japan; Department of Basic Veterinary Science, the United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193, Japan.
Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-Cho, Fuchu, Tokyo, 183-8509, Japan; Department of Basic Veterinary Science, the United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193, Japan.
Poult Sci. 2017 Sep 1;96(9):3436-3444. doi: 10.3382/ps/pex161.
Phytosterols (PS) are plant origin sterols naturally found in many foods and added as food additives. Since 1950, PS have attracted considerable attention due to their ability to lower serum cholesterol and inhibit cardiovascular disease (CVD). However, recent studies have found that PS act as endocrine-disrupting chemicals in laboratory animals. Therefore, this study was aimed at finding the mechanism(s) for PS effects on the sexual behaviors and reproductive functions in male Japanese quails (Coturnix coturnix japonica). At 15 d of age, 30 male Japanese quails were randomly assigned to 3 groups for the chronic in-vivo experiment. Animals were gavaged daily with single dose of PS suspension (PS dissolved in medium chain triglyceride [MCT]) into the crop sac from 15-100 d of age. Following maturation, a sexual behavior test, semen collection, and test of fertilization ability were performed. Blood was collected by cervical dislocation at 100 day of age for hormones analysis. To observe the direct effects of PS on the testis, interstitial cells of the normal testes were cultured for 24 h. Ovine-LH (O-LH) was used for half of each group to stimulate interstitial cells for testosterone production. The results showed that chronic doses of PS reduced (P < 0.01) mount and copulation behavior in male quails (primarily in the group receiving 800 mg/kg BW). Both acute in vitro and chronic in vivo experiments revealed a reduction in testosterone (P < 0.05) after PS treatments; concomitantly, Leydig cell numbers were also low (P < 0.05) at a dose of 800 mg/kg BW. Real-time PCR results showed lower expression of 17β-hydroxysteroid dehydrogenase (17β-HSD) at the same dose. The results suggested that feeding large amounts of PS reduced testosterone levels and sexual behavior by affecting Leydig cell proliferation, and cholesterol trafficking, 17β-HSD expression in the testes of male Japanese quail.
植物甾醇（PS）是植物来源的甾醇，天然存在于许多食物中，并作为食品添加剂添加。自 1950 年以来，由于 PS 能够降低血清胆固醇和抑制心血管疾病（CVD），因此引起了相当大的关注。然而，最近的研究发现，PS 作为内分泌干扰化学物质在实验动物中起作用。因此，本研究旨在寻找 PS 对雄性日本鹌鹑（Coturnix coturnix japonica）性行为和生殖功能影响的机制。在 15 日龄时，将 30 只雄性日本鹌鹑随机分配到 3 组进行慢性体内实验。动物从 15 至 100 日龄每天通过灌胃给予 PS 混悬液（PS 溶解于中链甘油三酯[MCT]中）。成熟后，进行性行为测试、精液采集和受精能力测试。在 100 日龄时通过颈椎脱位采集血液进行激素分析。为了观察 PS 对睾丸的直接影响，将正常睾丸间质细胞培养 24 小时。绵羊 LH（O-LH）用于每组的一半以刺激间质细胞产生睾酮。结果表明，慢性 PS 剂量降低了雄性鹌鹑（主要是接受 800mg/kg BW 的组）的交配和交配行为（P<0.01）。急性离体和慢性体内实验均显示 PS 处理后睾酮水平降低（P<0.05）；同时，在 800mg/kg BW 剂量下，Leydig 细胞数量也较低（P<0.05）。实时 PCR 结果显示在相同剂量下 17β-羟甾脱氢酶（17β-HSD）的表达较低。结果表明，大量喂养 PS 通过影响 Leydig 细胞增殖、胆固醇转运和睾丸中 17β-HSD 的表达，降低了雄性日本鹌鹑的睾酮水平和性行为。
